smpboot.c 35 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252125312541255125612571258125912601261126212631264126512661267126812691270127112721273127412751276127712781279128012811282128312841285128612871288128912901291129212931294129512961297129812991300130113021303130413051306130713081309131013111312131313141315131613171318131913201321132213231324132513261327132813291330133113321333133413351336133713381339134013411342134313441345134613471348134913501351135213531354135513561357135813591360136113621363136413651366136713681369137013711372137313741375137613771378137913801381138213831384138513861387138813891390139113921393139413951396139713981399140014011402140314041405140614071408140914101411141214131414141514161417141814191420142114221423142414251426142714281429143014311432143314341435143614371438143914401441144214431444144514461447144814491450
  1. /*
  2. * x86 SMP booting functions
  3. *
  4. * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
  5. * (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
  6. * Copyright 2001 Andi Kleen, SuSE Labs.
  7. *
  8. * Much of the core SMP work is based on previous work by Thomas Radke, to
  9. * whom a great many thanks are extended.
  10. *
  11. * Thanks to Intel for making available several different Pentium,
  12. * Pentium Pro and Pentium-II/Xeon MP machines.
  13. * Original development of Linux SMP code supported by Caldera.
  14. *
  15. * This code is released under the GNU General Public License version 2 or
  16. * later.
  17. *
  18. * Fixes
  19. * Felix Koop : NR_CPUS used properly
  20. * Jose Renau : Handle single CPU case.
  21. * Alan Cox : By repeated request 8) - Total BogoMIPS report.
  22. * Greg Wright : Fix for kernel stacks panic.
  23. * Erich Boleyn : MP v1.4 and additional changes.
  24. * Matthias Sattler : Changes for 2.1 kernel map.
  25. * Michel Lespinasse : Changes for 2.1 kernel map.
  26. * Michael Chastain : Change trampoline.S to gnu as.
  27. * Alan Cox : Dumb bug: 'B' step PPro's are fine
  28. * Ingo Molnar : Added APIC timers, based on code
  29. * from Jose Renau
  30. * Ingo Molnar : various cleanups and rewrites
  31. * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug.
  32. * Maciej W. Rozycki : Bits for genuine 82489DX APICs
  33. * Andi Kleen : Changed for SMP boot into long mode.
  34. * Martin J. Bligh : Added support for multi-quad systems
  35. * Dave Jones : Report invalid combinations of Athlon CPUs.
  36. * Rusty Russell : Hacked into shape for new "hotplug" boot process.
  37. * Andi Kleen : Converted to new state machine.
  38. * Ashok Raj : CPU hotplug support
  39. * Glauber Costa : i386 and x86_64 integration
  40. */
  41. #include <linux/init.h>
  42. #include <linux/smp.h>
  43. #include <linux/module.h>
  44. #include <linux/sched.h>
  45. #include <linux/percpu.h>
  46. #include <linux/bootmem.h>
  47. #include <linux/err.h>
  48. #include <linux/nmi.h>
  49. #include <asm/acpi.h>
  50. #include <asm/desc.h>
  51. #include <asm/nmi.h>
  52. #include <asm/irq.h>
  53. #include <asm/idle.h>
  54. #include <asm/smp.h>
  55. #include <asm/trampoline.h>
  56. #include <asm/cpu.h>
  57. #include <asm/numa.h>
  58. #include <asm/pgtable.h>
  59. #include <asm/tlbflush.h>
  60. #include <asm/mtrr.h>
  61. #include <asm/vmi.h>
  62. #include <asm/genapic.h>
  63. #include <asm/setup.h>
  64. #include <linux/mc146818rtc.h>
  65. #include <mach_apic.h>
  66. #include <mach_wakecpu.h>
  67. #include <smpboot_hooks.h>
  68. #ifdef CONFIG_X86_32
  69. u8 apicid_2_node[MAX_APICID];
  70. static int low_mappings;
  71. #endif
  72. /* State of each CPU */
  73. DEFINE_PER_CPU(int, cpu_state) = { 0 };
  74. /* Store all idle threads, this can be reused instead of creating
  75. * a new thread. Also avoids complicated thread destroy functionality
  76. * for idle threads.
  77. */
  78. #ifdef CONFIG_HOTPLUG_CPU
  79. /*
  80. * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
  81. * removed after init for !CONFIG_HOTPLUG_CPU.
  82. */
  83. static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
  84. #define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
  85. #define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
  86. #else
  87. static struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
  88. #define get_idle_for_cpu(x) (idle_thread_array[(x)])
  89. #define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
  90. #endif
  91. /* Number of siblings per CPU package */
  92. int smp_num_siblings = 1;
  93. EXPORT_SYMBOL(smp_num_siblings);
  94. /* Last level cache ID of each logical CPU */
  95. DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
  96. cpumask_t cpu_callin_map;
  97. cpumask_t cpu_callout_map;
  98. /* representing HT siblings of each logical CPU */
  99. DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
  100. EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
  101. /* representing HT and core siblings of each logical CPU */
  102. DEFINE_PER_CPU(cpumask_t, cpu_core_map);
  103. EXPORT_PER_CPU_SYMBOL(cpu_core_map);
  104. /* Per CPU bogomips and other parameters */
  105. DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
  106. EXPORT_PER_CPU_SYMBOL(cpu_info);
  107. static atomic_t init_deasserted;
  108. /* representing cpus for which sibling maps can be computed */
  109. static cpumask_t cpu_sibling_setup_map;
  110. /* Set if we find a B stepping CPU */
  111. static int __cpuinitdata smp_b_stepping;
  112. #if defined(CONFIG_NUMA) && defined(CONFIG_X86_32)
  113. /* which logical CPUs are on which nodes */
  114. cpumask_t node_to_cpumask_map[MAX_NUMNODES] __read_mostly =
  115. { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE };
  116. EXPORT_SYMBOL(node_to_cpumask_map);
  117. /* which node each logical CPU is on */
  118. int cpu_to_node_map[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0 };
  119. EXPORT_SYMBOL(cpu_to_node_map);
  120. /* set up a mapping between cpu and node. */
  121. static void map_cpu_to_node(int cpu, int node)
  122. {
  123. printk(KERN_INFO "Mapping cpu %d to node %d\n", cpu, node);
  124. cpu_set(cpu, node_to_cpumask_map[node]);
  125. cpu_to_node_map[cpu] = node;
  126. }
  127. /* undo a mapping between cpu and node. */
  128. static void unmap_cpu_to_node(int cpu)
  129. {
  130. int node;
  131. printk(KERN_INFO "Unmapping cpu %d from all nodes\n", cpu);
  132. for (node = 0; node < MAX_NUMNODES; node++)
  133. cpu_clear(cpu, node_to_cpumask_map[node]);
  134. cpu_to_node_map[cpu] = 0;
  135. }
  136. #else /* !(CONFIG_NUMA && CONFIG_X86_32) */
  137. #define map_cpu_to_node(cpu, node) ({})
  138. #define unmap_cpu_to_node(cpu) ({})
  139. #endif
  140. #ifdef CONFIG_X86_32
  141. static int boot_cpu_logical_apicid;
  142. u8 cpu_2_logical_apicid[NR_CPUS] __read_mostly =
  143. { [0 ... NR_CPUS-1] = BAD_APICID };
  144. static void map_cpu_to_logical_apicid(void)
  145. {
  146. int cpu = smp_processor_id();
  147. int apicid = logical_smp_processor_id();
  148. int node = apicid_to_node(apicid);
  149. if (!node_online(node))
  150. node = first_online_node;
  151. cpu_2_logical_apicid[cpu] = apicid;
  152. map_cpu_to_node(cpu, node);
  153. }
  154. void numa_remove_cpu(int cpu)
  155. {
  156. cpu_2_logical_apicid[cpu] = BAD_APICID;
  157. unmap_cpu_to_node(cpu);
  158. }
  159. #else
  160. #define map_cpu_to_logical_apicid() do {} while (0)
  161. #endif
  162. /*
  163. * Report back to the Boot Processor.
  164. * Running on AP.
  165. */
  166. static void __cpuinit smp_callin(void)
  167. {
  168. int cpuid, phys_id;
  169. unsigned long timeout;
  170. /*
  171. * If waken up by an INIT in an 82489DX configuration
  172. * we may get here before an INIT-deassert IPI reaches
  173. * our local APIC. We have to wait for the IPI or we'll
  174. * lock up on an APIC access.
  175. */
  176. wait_for_init_deassert(&init_deasserted);
  177. /*
  178. * (This works even if the APIC is not enabled.)
  179. */
  180. phys_id = read_apic_id();
  181. cpuid = smp_processor_id();
  182. if (cpu_isset(cpuid, cpu_callin_map)) {
  183. panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
  184. phys_id, cpuid);
  185. }
  186. pr_debug("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
  187. /*
  188. * STARTUP IPIs are fragile beasts as they might sometimes
  189. * trigger some glue motherboard logic. Complete APIC bus
  190. * silence for 1 second, this overestimates the time the
  191. * boot CPU is spending to send the up to 2 STARTUP IPIs
  192. * by a factor of two. This should be enough.
  193. */
  194. /*
  195. * Waiting 2s total for startup (udelay is not yet working)
  196. */
  197. timeout = jiffies + 2*HZ;
  198. while (time_before(jiffies, timeout)) {
  199. /*
  200. * Has the boot CPU finished it's STARTUP sequence?
  201. */
  202. if (cpu_isset(cpuid, cpu_callout_map))
  203. break;
  204. cpu_relax();
  205. }
  206. if (!time_before(jiffies, timeout)) {
  207. panic("%s: CPU%d started up but did not get a callout!\n",
  208. __func__, cpuid);
  209. }
  210. /*
  211. * the boot CPU has finished the init stage and is spinning
  212. * on callin_map until we finish. We are free to set up this
  213. * CPU, first the APIC. (this is probably redundant on most
  214. * boards)
  215. */
  216. pr_debug("CALLIN, before setup_local_APIC().\n");
  217. smp_callin_clear_local_apic();
  218. setup_local_APIC();
  219. end_local_APIC_setup();
  220. map_cpu_to_logical_apicid();
  221. notify_cpu_starting(cpuid);
  222. /*
  223. * Get our bogomips.
  224. *
  225. * Need to enable IRQs because it can take longer and then
  226. * the NMI watchdog might kill us.
  227. */
  228. local_irq_enable();
  229. calibrate_delay();
  230. local_irq_disable();
  231. pr_debug("Stack at about %p\n", &cpuid);
  232. /*
  233. * Save our processor parameters
  234. */
  235. smp_store_cpu_info(cpuid);
  236. /*
  237. * Allow the master to continue.
  238. */
  239. cpu_set(cpuid, cpu_callin_map);
  240. }
  241. static int __cpuinitdata unsafe_smp;
  242. /*
  243. * Activate a secondary processor.
  244. */
  245. notrace static void __cpuinit start_secondary(void *unused)
  246. {
  247. /*
  248. * Don't put *anything* before cpu_init(), SMP booting is too
  249. * fragile that we want to limit the things done here to the
  250. * most necessary things.
  251. */
  252. vmi_bringup();
  253. cpu_init();
  254. preempt_disable();
  255. smp_callin();
  256. /* otherwise gcc will move up smp_processor_id before the cpu_init */
  257. barrier();
  258. /*
  259. * Check TSC synchronization with the BP:
  260. */
  261. check_tsc_sync_target();
  262. if (nmi_watchdog == NMI_IO_APIC) {
  263. disable_8259A_irq(0);
  264. enable_NMI_through_LVT0();
  265. enable_8259A_irq(0);
  266. }
  267. #ifdef CONFIG_X86_32
  268. while (low_mappings)
  269. cpu_relax();
  270. __flush_tlb_all();
  271. #endif
  272. /* This must be done before setting cpu_online_map */
  273. set_cpu_sibling_map(raw_smp_processor_id());
  274. wmb();
  275. /*
  276. * We need to hold call_lock, so there is no inconsistency
  277. * between the time smp_call_function() determines number of
  278. * IPI recipients, and the time when the determination is made
  279. * for which cpus receive the IPI. Holding this
  280. * lock helps us to not include this cpu in a currently in progress
  281. * smp_call_function().
  282. *
  283. * We need to hold vector_lock so there the set of online cpus
  284. * does not change while we are assigning vectors to cpus. Holding
  285. * this lock ensures we don't half assign or remove an irq from a cpu.
  286. */
  287. ipi_call_lock();
  288. lock_vector_lock();
  289. __setup_vector_irq(smp_processor_id());
  290. cpu_set(smp_processor_id(), cpu_online_map);
  291. unlock_vector_lock();
  292. ipi_call_unlock();
  293. per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
  294. /* enable local interrupts */
  295. local_irq_enable();
  296. setup_secondary_clock();
  297. wmb();
  298. cpu_idle();
  299. }
  300. static void __cpuinit smp_apply_quirks(struct cpuinfo_x86 *c)
  301. {
  302. /*
  303. * Mask B, Pentium, but not Pentium MMX
  304. */
  305. if (c->x86_vendor == X86_VENDOR_INTEL &&
  306. c->x86 == 5 &&
  307. c->x86_mask >= 1 && c->x86_mask <= 4 &&
  308. c->x86_model <= 3)
  309. /*
  310. * Remember we have B step Pentia with bugs
  311. */
  312. smp_b_stepping = 1;
  313. /*
  314. * Certain Athlons might work (for various values of 'work') in SMP
  315. * but they are not certified as MP capable.
  316. */
  317. if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) {
  318. if (num_possible_cpus() == 1)
  319. goto valid_k7;
  320. /* Athlon 660/661 is valid. */
  321. if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
  322. (c->x86_mask == 1)))
  323. goto valid_k7;
  324. /* Duron 670 is valid */
  325. if ((c->x86_model == 7) && (c->x86_mask == 0))
  326. goto valid_k7;
  327. /*
  328. * Athlon 662, Duron 671, and Athlon >model 7 have capability
  329. * bit. It's worth noting that the A5 stepping (662) of some
  330. * Athlon XP's have the MP bit set.
  331. * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
  332. * more.
  333. */
  334. if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
  335. ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
  336. (c->x86_model > 7))
  337. if (cpu_has_mp)
  338. goto valid_k7;
  339. /* If we get here, not a certified SMP capable AMD system. */
  340. unsafe_smp = 1;
  341. }
  342. valid_k7:
  343. ;
  344. }
  345. static void __cpuinit smp_checks(void)
  346. {
  347. if (smp_b_stepping)
  348. printk(KERN_WARNING "WARNING: SMP operation may be unreliable"
  349. "with B stepping processors.\n");
  350. /*
  351. * Don't taint if we are running SMP kernel on a single non-MP
  352. * approved Athlon
  353. */
  354. if (unsafe_smp && num_online_cpus() > 1) {
  355. printk(KERN_INFO "WARNING: This combination of AMD"
  356. "processors is not suitable for SMP.\n");
  357. add_taint(TAINT_UNSAFE_SMP);
  358. }
  359. }
  360. /*
  361. * The bootstrap kernel entry code has set these up. Save them for
  362. * a given CPU
  363. */
  364. void __cpuinit smp_store_cpu_info(int id)
  365. {
  366. struct cpuinfo_x86 *c = &cpu_data(id);
  367. *c = boot_cpu_data;
  368. c->cpu_index = id;
  369. if (id != 0)
  370. identify_secondary_cpu(c);
  371. smp_apply_quirks(c);
  372. }
  373. void __cpuinit set_cpu_sibling_map(int cpu)
  374. {
  375. int i;
  376. struct cpuinfo_x86 *c = &cpu_data(cpu);
  377. cpu_set(cpu, cpu_sibling_setup_map);
  378. if (smp_num_siblings > 1) {
  379. for_each_cpu_mask_nr(i, cpu_sibling_setup_map) {
  380. if (c->phys_proc_id == cpu_data(i).phys_proc_id &&
  381. c->cpu_core_id == cpu_data(i).cpu_core_id) {
  382. cpu_set(i, per_cpu(cpu_sibling_map, cpu));
  383. cpu_set(cpu, per_cpu(cpu_sibling_map, i));
  384. cpu_set(i, per_cpu(cpu_core_map, cpu));
  385. cpu_set(cpu, per_cpu(cpu_core_map, i));
  386. cpu_set(i, c->llc_shared_map);
  387. cpu_set(cpu, cpu_data(i).llc_shared_map);
  388. }
  389. }
  390. } else {
  391. cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
  392. }
  393. cpu_set(cpu, c->llc_shared_map);
  394. if (current_cpu_data.x86_max_cores == 1) {
  395. per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
  396. c->booted_cores = 1;
  397. return;
  398. }
  399. for_each_cpu_mask_nr(i, cpu_sibling_setup_map) {
  400. if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
  401. per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
  402. cpu_set(i, c->llc_shared_map);
  403. cpu_set(cpu, cpu_data(i).llc_shared_map);
  404. }
  405. if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
  406. cpu_set(i, per_cpu(cpu_core_map, cpu));
  407. cpu_set(cpu, per_cpu(cpu_core_map, i));
  408. /*
  409. * Does this new cpu bringup a new core?
  410. */
  411. if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) {
  412. /*
  413. * for each core in package, increment
  414. * the booted_cores for this new cpu
  415. */
  416. if (first_cpu(per_cpu(cpu_sibling_map, i)) == i)
  417. c->booted_cores++;
  418. /*
  419. * increment the core count for all
  420. * the other cpus in this package
  421. */
  422. if (i != cpu)
  423. cpu_data(i).booted_cores++;
  424. } else if (i != cpu && !c->booted_cores)
  425. c->booted_cores = cpu_data(i).booted_cores;
  426. }
  427. }
  428. }
  429. /* maps the cpu to the sched domain representing multi-core */
  430. cpumask_t cpu_coregroup_map(int cpu)
  431. {
  432. struct cpuinfo_x86 *c = &cpu_data(cpu);
  433. /*
  434. * For perf, we return last level cache shared map.
  435. * And for power savings, we return cpu_core_map
  436. */
  437. if (sched_mc_power_savings || sched_smt_power_savings)
  438. return per_cpu(cpu_core_map, cpu);
  439. else
  440. return c->llc_shared_map;
  441. }
  442. static void impress_friends(void)
  443. {
  444. int cpu;
  445. unsigned long bogosum = 0;
  446. /*
  447. * Allow the user to impress friends.
  448. */
  449. pr_debug("Before bogomips.\n");
  450. for_each_possible_cpu(cpu)
  451. if (cpu_isset(cpu, cpu_callout_map))
  452. bogosum += cpu_data(cpu).loops_per_jiffy;
  453. printk(KERN_INFO
  454. "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
  455. num_online_cpus(),
  456. bogosum/(500000/HZ),
  457. (bogosum/(5000/HZ))%100);
  458. pr_debug("Before bogocount - setting activated=1.\n");
  459. }
  460. void __inquire_remote_apic(int apicid)
  461. {
  462. unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
  463. char *names[] = { "ID", "VERSION", "SPIV" };
  464. int timeout;
  465. u32 status;
  466. printk(KERN_INFO "Inquiring remote APIC 0x%x...\n", apicid);
  467. for (i = 0; i < ARRAY_SIZE(regs); i++) {
  468. printk(KERN_INFO "... APIC 0x%x %s: ", apicid, names[i]);
  469. /*
  470. * Wait for idle.
  471. */
  472. status = safe_apic_wait_icr_idle();
  473. if (status)
  474. printk(KERN_CONT
  475. "a previous APIC delivery may have failed\n");
  476. apic_icr_write(APIC_DM_REMRD | regs[i], apicid);
  477. timeout = 0;
  478. do {
  479. udelay(100);
  480. status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
  481. } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
  482. switch (status) {
  483. case APIC_ICR_RR_VALID:
  484. status = apic_read(APIC_RRR);
  485. printk(KERN_CONT "%08x\n", status);
  486. break;
  487. default:
  488. printk(KERN_CONT "failed\n");
  489. }
  490. }
  491. }
  492. /*
  493. * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
  494. * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
  495. * won't ... remember to clear down the APIC, etc later.
  496. */
  497. int __devinit
  498. wakeup_secondary_cpu_via_nmi(int logical_apicid, unsigned long start_eip)
  499. {
  500. unsigned long send_status, accept_status = 0;
  501. int maxlvt;
  502. /* Target chip */
  503. /* Boot on the stack */
  504. /* Kick the second */
  505. apic_icr_write(APIC_DM_NMI | APIC_DEST_LOGICAL, logical_apicid);
  506. pr_debug("Waiting for send to finish...\n");
  507. send_status = safe_apic_wait_icr_idle();
  508. /*
  509. * Give the other CPU some time to accept the IPI.
  510. */
  511. udelay(200);
  512. if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
  513. maxlvt = lapic_get_maxlvt();
  514. if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
  515. apic_write(APIC_ESR, 0);
  516. accept_status = (apic_read(APIC_ESR) & 0xEF);
  517. }
  518. pr_debug("NMI sent.\n");
  519. if (send_status)
  520. printk(KERN_ERR "APIC never delivered???\n");
  521. if (accept_status)
  522. printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
  523. return (send_status | accept_status);
  524. }
  525. int __devinit
  526. wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
  527. {
  528. unsigned long send_status, accept_status = 0;
  529. int maxlvt, num_starts, j;
  530. if (get_uv_system_type() == UV_NON_UNIQUE_APIC) {
  531. send_status = uv_wakeup_secondary(phys_apicid, start_eip);
  532. atomic_set(&init_deasserted, 1);
  533. return send_status;
  534. }
  535. maxlvt = lapic_get_maxlvt();
  536. /*
  537. * Be paranoid about clearing APIC errors.
  538. */
  539. if (APIC_INTEGRATED(apic_version[phys_apicid])) {
  540. if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
  541. apic_write(APIC_ESR, 0);
  542. apic_read(APIC_ESR);
  543. }
  544. pr_debug("Asserting INIT.\n");
  545. /*
  546. * Turn INIT on target chip
  547. */
  548. /*
  549. * Send IPI
  550. */
  551. apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT,
  552. phys_apicid);
  553. pr_debug("Waiting for send to finish...\n");
  554. send_status = safe_apic_wait_icr_idle();
  555. mdelay(10);
  556. pr_debug("Deasserting INIT.\n");
  557. /* Target chip */
  558. /* Send IPI */
  559. apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid);
  560. pr_debug("Waiting for send to finish...\n");
  561. send_status = safe_apic_wait_icr_idle();
  562. mb();
  563. atomic_set(&init_deasserted, 1);
  564. /*
  565. * Should we send STARTUP IPIs ?
  566. *
  567. * Determine this based on the APIC version.
  568. * If we don't have an integrated APIC, don't send the STARTUP IPIs.
  569. */
  570. if (APIC_INTEGRATED(apic_version[phys_apicid]))
  571. num_starts = 2;
  572. else
  573. num_starts = 0;
  574. /*
  575. * Paravirt / VMI wants a startup IPI hook here to set up the
  576. * target processor state.
  577. */
  578. startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
  579. (unsigned long)stack_start.sp);
  580. /*
  581. * Run STARTUP IPI loop.
  582. */
  583. pr_debug("#startup loops: %d.\n", num_starts);
  584. for (j = 1; j <= num_starts; j++) {
  585. pr_debug("Sending STARTUP #%d.\n", j);
  586. if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
  587. apic_write(APIC_ESR, 0);
  588. apic_read(APIC_ESR);
  589. pr_debug("After apic_write.\n");
  590. /*
  591. * STARTUP IPI
  592. */
  593. /* Target chip */
  594. /* Boot on the stack */
  595. /* Kick the second */
  596. apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12),
  597. phys_apicid);
  598. /*
  599. * Give the other CPU some time to accept the IPI.
  600. */
  601. udelay(300);
  602. pr_debug("Startup point 1.\n");
  603. pr_debug("Waiting for send to finish...\n");
  604. send_status = safe_apic_wait_icr_idle();
  605. /*
  606. * Give the other CPU some time to accept the IPI.
  607. */
  608. udelay(200);
  609. if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
  610. apic_write(APIC_ESR, 0);
  611. accept_status = (apic_read(APIC_ESR) & 0xEF);
  612. if (send_status || accept_status)
  613. break;
  614. }
  615. pr_debug("After Startup.\n");
  616. if (send_status)
  617. printk(KERN_ERR "APIC never delivered???\n");
  618. if (accept_status)
  619. printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
  620. return (send_status | accept_status);
  621. }
  622. struct create_idle {
  623. struct work_struct work;
  624. struct task_struct *idle;
  625. struct completion done;
  626. int cpu;
  627. };
  628. static void __cpuinit do_fork_idle(struct work_struct *work)
  629. {
  630. struct create_idle *c_idle =
  631. container_of(work, struct create_idle, work);
  632. c_idle->idle = fork_idle(c_idle->cpu);
  633. complete(&c_idle->done);
  634. }
  635. #ifdef CONFIG_X86_64
  636. /* __ref because it's safe to call free_bootmem when after_bootmem == 0. */
  637. static void __ref free_bootmem_pda(struct x8664_pda *oldpda)
  638. {
  639. if (!after_bootmem)
  640. free_bootmem((unsigned long)oldpda, sizeof(*oldpda));
  641. }
  642. /*
  643. * Allocate node local memory for the AP pda.
  644. *
  645. * Must be called after the _cpu_pda pointer table is initialized.
  646. */
  647. int __cpuinit get_local_pda(int cpu)
  648. {
  649. struct x8664_pda *oldpda, *newpda;
  650. unsigned long size = sizeof(struct x8664_pda);
  651. int node = cpu_to_node(cpu);
  652. if (cpu_pda(cpu) && !cpu_pda(cpu)->in_bootmem)
  653. return 0;
  654. oldpda = cpu_pda(cpu);
  655. newpda = kmalloc_node(size, GFP_ATOMIC, node);
  656. if (!newpda) {
  657. printk(KERN_ERR "Could not allocate node local PDA "
  658. "for CPU %d on node %d\n", cpu, node);
  659. if (oldpda)
  660. return 0; /* have a usable pda */
  661. else
  662. return -1;
  663. }
  664. if (oldpda) {
  665. memcpy(newpda, oldpda, size);
  666. free_bootmem_pda(oldpda);
  667. }
  668. newpda->in_bootmem = 0;
  669. cpu_pda(cpu) = newpda;
  670. return 0;
  671. }
  672. #endif /* CONFIG_X86_64 */
  673. static int __cpuinit do_boot_cpu(int apicid, int cpu)
  674. /*
  675. * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
  676. * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
  677. * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
  678. */
  679. {
  680. unsigned long boot_error = 0;
  681. int timeout;
  682. unsigned long start_ip;
  683. unsigned short nmi_high = 0, nmi_low = 0;
  684. struct create_idle c_idle = {
  685. .cpu = cpu,
  686. .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
  687. };
  688. INIT_WORK(&c_idle.work, do_fork_idle);
  689. #ifdef CONFIG_X86_64
  690. /* Allocate node local memory for AP pdas */
  691. if (cpu > 0) {
  692. boot_error = get_local_pda(cpu);
  693. if (boot_error)
  694. goto restore_state;
  695. /* if can't get pda memory, can't start cpu */
  696. }
  697. #endif
  698. alternatives_smp_switch(1);
  699. c_idle.idle = get_idle_for_cpu(cpu);
  700. /*
  701. * We can't use kernel_thread since we must avoid to
  702. * reschedule the child.
  703. */
  704. if (c_idle.idle) {
  705. c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *)
  706. (THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
  707. init_idle(c_idle.idle, cpu);
  708. goto do_rest;
  709. }
  710. if (!keventd_up() || current_is_keventd())
  711. c_idle.work.func(&c_idle.work);
  712. else {
  713. schedule_work(&c_idle.work);
  714. wait_for_completion(&c_idle.done);
  715. }
  716. if (IS_ERR(c_idle.idle)) {
  717. printk("failed fork for CPU %d\n", cpu);
  718. return PTR_ERR(c_idle.idle);
  719. }
  720. set_idle_for_cpu(cpu, c_idle.idle);
  721. do_rest:
  722. #ifdef CONFIG_X86_32
  723. per_cpu(current_task, cpu) = c_idle.idle;
  724. init_gdt(cpu);
  725. /* Stack for startup_32 can be just as for start_secondary onwards */
  726. irq_ctx_init(cpu);
  727. #else
  728. cpu_pda(cpu)->pcurrent = c_idle.idle;
  729. clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
  730. #endif
  731. early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
  732. initial_code = (unsigned long)start_secondary;
  733. stack_start.sp = (void *) c_idle.idle->thread.sp;
  734. /* start_ip had better be page-aligned! */
  735. start_ip = setup_trampoline();
  736. /* So we see what's up */
  737. printk(KERN_INFO "Booting processor %d APIC 0x%x ip 0x%lx\n",
  738. cpu, apicid, start_ip);
  739. /*
  740. * This grunge runs the startup process for
  741. * the targeted processor.
  742. */
  743. atomic_set(&init_deasserted, 0);
  744. if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
  745. pr_debug("Setting warm reset code and vector.\n");
  746. store_NMI_vector(&nmi_high, &nmi_low);
  747. smpboot_setup_warm_reset_vector(start_ip);
  748. /*
  749. * Be paranoid about clearing APIC errors.
  750. */
  751. if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
  752. apic_write(APIC_ESR, 0);
  753. apic_read(APIC_ESR);
  754. }
  755. }
  756. /*
  757. * Starting actual IPI sequence...
  758. */
  759. boot_error = wakeup_secondary_cpu(apicid, start_ip);
  760. if (!boot_error) {
  761. /*
  762. * allow APs to start initializing.
  763. */
  764. pr_debug("Before Callout %d.\n", cpu);
  765. cpu_set(cpu, cpu_callout_map);
  766. pr_debug("After Callout %d.\n", cpu);
  767. /*
  768. * Wait 5s total for a response
  769. */
  770. for (timeout = 0; timeout < 50000; timeout++) {
  771. if (cpu_isset(cpu, cpu_callin_map))
  772. break; /* It has booted */
  773. udelay(100);
  774. }
  775. if (cpu_isset(cpu, cpu_callin_map)) {
  776. /* number CPUs logically, starting from 1 (BSP is 0) */
  777. pr_debug("OK.\n");
  778. printk(KERN_INFO "CPU%d: ", cpu);
  779. print_cpu_info(&cpu_data(cpu));
  780. pr_debug("CPU has booted.\n");
  781. } else {
  782. boot_error = 1;
  783. if (*((volatile unsigned char *)trampoline_base)
  784. == 0xA5)
  785. /* trampoline started but...? */
  786. printk(KERN_ERR "Stuck ??\n");
  787. else
  788. /* trampoline code not run */
  789. printk(KERN_ERR "Not responding.\n");
  790. if (get_uv_system_type() != UV_NON_UNIQUE_APIC)
  791. inquire_remote_apic(apicid);
  792. }
  793. }
  794. #ifdef CONFIG_X86_64
  795. restore_state:
  796. #endif
  797. if (boot_error) {
  798. /* Try to put things back the way they were before ... */
  799. numa_remove_cpu(cpu); /* was set by numa_add_cpu */
  800. cpu_clear(cpu, cpu_callout_map); /* was set by do_boot_cpu() */
  801. cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
  802. cpu_clear(cpu, cpu_present_map);
  803. per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
  804. }
  805. /* mark "stuck" area as not stuck */
  806. *((volatile unsigned long *)trampoline_base) = 0;
  807. /*
  808. * Cleanup possible dangling ends...
  809. */
  810. smpboot_restore_warm_reset_vector();
  811. return boot_error;
  812. }
  813. int __cpuinit native_cpu_up(unsigned int cpu)
  814. {
  815. int apicid = cpu_present_to_apicid(cpu);
  816. unsigned long flags;
  817. int err;
  818. WARN_ON(irqs_disabled());
  819. pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);
  820. if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
  821. !physid_isset(apicid, phys_cpu_present_map)) {
  822. printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
  823. return -EINVAL;
  824. }
  825. /*
  826. * Already booted CPU?
  827. */
  828. if (cpu_isset(cpu, cpu_callin_map)) {
  829. pr_debug("do_boot_cpu %d Already started\n", cpu);
  830. return -ENOSYS;
  831. }
  832. /*
  833. * Save current MTRR state in case it was changed since early boot
  834. * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
  835. */
  836. mtrr_save_state();
  837. per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
  838. #ifdef CONFIG_X86_32
  839. /* init low mem mapping */
  840. clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
  841. min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
  842. flush_tlb_all();
  843. low_mappings = 1;
  844. err = do_boot_cpu(apicid, cpu);
  845. zap_low_mappings();
  846. low_mappings = 0;
  847. #else
  848. err = do_boot_cpu(apicid, cpu);
  849. #endif
  850. if (err) {
  851. pr_debug("do_boot_cpu failed %d\n", err);
  852. return -EIO;
  853. }
  854. /*
  855. * Check TSC synchronization with the AP (keep irqs disabled
  856. * while doing so):
  857. */
  858. local_irq_save(flags);
  859. check_tsc_sync_source(cpu);
  860. local_irq_restore(flags);
  861. while (!cpu_online(cpu)) {
  862. cpu_relax();
  863. touch_nmi_watchdog();
  864. }
  865. return 0;
  866. }
  867. /*
  868. * Fall back to non SMP mode after errors.
  869. *
  870. * RED-PEN audit/test this more. I bet there is more state messed up here.
  871. */
  872. static __init void disable_smp(void)
  873. {
  874. cpu_present_map = cpumask_of_cpu(0);
  875. cpu_possible_map = cpumask_of_cpu(0);
  876. smpboot_clear_io_apic_irqs();
  877. if (smp_found_config)
  878. physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
  879. else
  880. physid_set_mask_of_physid(0, &phys_cpu_present_map);
  881. map_cpu_to_logical_apicid();
  882. cpu_set(0, per_cpu(cpu_sibling_map, 0));
  883. cpu_set(0, per_cpu(cpu_core_map, 0));
  884. }
  885. /*
  886. * Various sanity checks.
  887. */
  888. static int __init smp_sanity_check(unsigned max_cpus)
  889. {
  890. preempt_disable();
  891. #if defined(CONFIG_X86_PC) && defined(CONFIG_X86_32)
  892. if (def_to_bigsmp && nr_cpu_ids > 8) {
  893. unsigned int cpu;
  894. unsigned nr;
  895. printk(KERN_WARNING
  896. "More than 8 CPUs detected - skipping them.\n"
  897. "Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.\n");
  898. nr = 0;
  899. for_each_present_cpu(cpu) {
  900. if (nr >= 8)
  901. cpu_clear(cpu, cpu_present_map);
  902. nr++;
  903. }
  904. nr = 0;
  905. for_each_possible_cpu(cpu) {
  906. if (nr >= 8)
  907. cpu_clear(cpu, cpu_possible_map);
  908. nr++;
  909. }
  910. nr_cpu_ids = 8;
  911. }
  912. #endif
  913. if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
  914. printk(KERN_WARNING
  915. "weird, boot CPU (#%d) not listed by the BIOS.\n",
  916. hard_smp_processor_id());
  917. physid_set(hard_smp_processor_id(), phys_cpu_present_map);
  918. }
  919. /*
  920. * If we couldn't find an SMP configuration at boot time,
  921. * get out of here now!
  922. */
  923. if (!smp_found_config && !acpi_lapic) {
  924. preempt_enable();
  925. printk(KERN_NOTICE "SMP motherboard not detected.\n");
  926. disable_smp();
  927. if (APIC_init_uniprocessor())
  928. printk(KERN_NOTICE "Local APIC not detected."
  929. " Using dummy APIC emulation.\n");
  930. return -1;
  931. }
  932. /*
  933. * Should not be necessary because the MP table should list the boot
  934. * CPU too, but we do it for the sake of robustness anyway.
  935. */
  936. if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
  937. printk(KERN_NOTICE
  938. "weird, boot CPU (#%d) not listed by the BIOS.\n",
  939. boot_cpu_physical_apicid);
  940. physid_set(hard_smp_processor_id(), phys_cpu_present_map);
  941. }
  942. preempt_enable();
  943. /*
  944. * If we couldn't find a local APIC, then get out of here now!
  945. */
  946. if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
  947. !cpu_has_apic) {
  948. printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
  949. boot_cpu_physical_apicid);
  950. printk(KERN_ERR "... forcing use of dummy APIC emulation."
  951. "(tell your hw vendor)\n");
  952. smpboot_clear_io_apic();
  953. return -1;
  954. }
  955. verify_local_APIC();
  956. /*
  957. * If SMP should be disabled, then really disable it!
  958. */
  959. if (!max_cpus) {
  960. printk(KERN_INFO "SMP mode deactivated.\n");
  961. smpboot_clear_io_apic();
  962. localise_nmi_watchdog();
  963. connect_bsp_APIC();
  964. setup_local_APIC();
  965. end_local_APIC_setup();
  966. return -1;
  967. }
  968. return 0;
  969. }
  970. static void __init smp_cpu_index_default(void)
  971. {
  972. int i;
  973. struct cpuinfo_x86 *c;
  974. for_each_possible_cpu(i) {
  975. c = &cpu_data(i);
  976. /* mark all to hotplug */
  977. c->cpu_index = NR_CPUS;
  978. }
  979. }
  980. /*
  981. * Prepare for SMP bootup. The MP table or ACPI has been read
  982. * earlier. Just do some sanity checking here and enable APIC mode.
  983. */
  984. void __init native_smp_prepare_cpus(unsigned int max_cpus)
  985. {
  986. preempt_disable();
  987. smp_cpu_index_default();
  988. current_cpu_data = boot_cpu_data;
  989. cpu_callin_map = cpumask_of_cpu(0);
  990. mb();
  991. /*
  992. * Setup boot CPU information
  993. */
  994. smp_store_cpu_info(0); /* Final full version of the data */
  995. #ifdef CONFIG_X86_32
  996. boot_cpu_logical_apicid = logical_smp_processor_id();
  997. #endif
  998. current_thread_info()->cpu = 0; /* needed? */
  999. set_cpu_sibling_map(0);
  1000. #ifdef CONFIG_X86_64
  1001. enable_IR_x2apic();
  1002. setup_apic_routing();
  1003. #endif
  1004. if (smp_sanity_check(max_cpus) < 0) {
  1005. printk(KERN_INFO "SMP disabled\n");
  1006. disable_smp();
  1007. goto out;
  1008. }
  1009. preempt_disable();
  1010. if (read_apic_id() != boot_cpu_physical_apicid) {
  1011. panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
  1012. read_apic_id(), boot_cpu_physical_apicid);
  1013. /* Or can we switch back to PIC here? */
  1014. }
  1015. preempt_enable();
  1016. connect_bsp_APIC();
  1017. /*
  1018. * Switch from PIC to APIC mode.
  1019. */
  1020. setup_local_APIC();
  1021. #ifdef CONFIG_X86_64
  1022. /*
  1023. * Enable IO APIC before setting up error vector
  1024. */
  1025. if (!skip_ioapic_setup && nr_ioapics)
  1026. enable_IO_APIC();
  1027. #endif
  1028. end_local_APIC_setup();
  1029. map_cpu_to_logical_apicid();
  1030. setup_portio_remap();
  1031. smpboot_setup_io_apic();
  1032. /*
  1033. * Set up local APIC timer on boot CPU.
  1034. */
  1035. printk(KERN_INFO "CPU%d: ", 0);
  1036. print_cpu_info(&cpu_data(0));
  1037. setup_boot_clock();
  1038. if (is_uv_system())
  1039. uv_system_init();
  1040. out:
  1041. preempt_enable();
  1042. }
  1043. /*
  1044. * Early setup to make printk work.
  1045. */
  1046. void __init native_smp_prepare_boot_cpu(void)
  1047. {
  1048. int me = smp_processor_id();
  1049. #ifdef CONFIG_X86_32
  1050. init_gdt(me);
  1051. #endif
  1052. switch_to_new_gdt();
  1053. /* already set me in cpu_online_map in boot_cpu_init() */
  1054. cpu_set(me, cpu_callout_map);
  1055. per_cpu(cpu_state, me) = CPU_ONLINE;
  1056. }
  1057. void __init native_smp_cpus_done(unsigned int max_cpus)
  1058. {
  1059. pr_debug("Boot done.\n");
  1060. impress_friends();
  1061. smp_checks();
  1062. #ifdef CONFIG_X86_IO_APIC
  1063. setup_ioapic_dest();
  1064. #endif
  1065. check_nmi_watchdog();
  1066. }
  1067. static int __initdata setup_possible_cpus = -1;
  1068. static int __init _setup_possible_cpus(char *str)
  1069. {
  1070. get_option(&str, &setup_possible_cpus);
  1071. return 0;
  1072. }
  1073. early_param("possible_cpus", _setup_possible_cpus);
  1074. /*
  1075. * cpu_possible_map should be static, it cannot change as cpu's
  1076. * are onlined, or offlined. The reason is per-cpu data-structures
  1077. * are allocated by some modules at init time, and dont expect to
  1078. * do this dynamically on cpu arrival/departure.
  1079. * cpu_present_map on the other hand can change dynamically.
  1080. * In case when cpu_hotplug is not compiled, then we resort to current
  1081. * behaviour, which is cpu_possible == cpu_present.
  1082. * - Ashok Raj
  1083. *
  1084. * Three ways to find out the number of additional hotplug CPUs:
  1085. * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
  1086. * - The user can overwrite it with possible_cpus=NUM
  1087. * - Otherwise don't reserve additional CPUs.
  1088. * We do this because additional CPUs waste a lot of memory.
  1089. * -AK
  1090. */
  1091. __init void prefill_possible_map(void)
  1092. {
  1093. int i, possible;
  1094. /* no processor from mptable or madt */
  1095. if (!num_processors)
  1096. num_processors = 1;
  1097. if (setup_possible_cpus == -1)
  1098. possible = num_processors + disabled_cpus;
  1099. else
  1100. possible = setup_possible_cpus;
  1101. if (possible > CONFIG_NR_CPUS) {
  1102. printk(KERN_WARNING
  1103. "%d Processors exceeds NR_CPUS limit of %d\n",
  1104. possible, CONFIG_NR_CPUS);
  1105. possible = CONFIG_NR_CPUS;
  1106. }
  1107. printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
  1108. possible, max_t(int, possible - num_processors, 0));
  1109. for (i = 0; i < possible; i++)
  1110. cpu_set(i, cpu_possible_map);
  1111. nr_cpu_ids = possible;
  1112. }
  1113. #ifdef CONFIG_HOTPLUG_CPU
  1114. static void remove_siblinginfo(int cpu)
  1115. {
  1116. int sibling;
  1117. struct cpuinfo_x86 *c = &cpu_data(cpu);
  1118. for_each_cpu_mask_nr(sibling, per_cpu(cpu_core_map, cpu)) {
  1119. cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
  1120. /*/
  1121. * last thread sibling in this cpu core going down
  1122. */
  1123. if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1)
  1124. cpu_data(sibling).booted_cores--;
  1125. }
  1126. for_each_cpu_mask_nr(sibling, per_cpu(cpu_sibling_map, cpu))
  1127. cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling));
  1128. cpus_clear(per_cpu(cpu_sibling_map, cpu));
  1129. cpus_clear(per_cpu(cpu_core_map, cpu));
  1130. c->phys_proc_id = 0;
  1131. c->cpu_core_id = 0;
  1132. cpu_clear(cpu, cpu_sibling_setup_map);
  1133. }
  1134. static void __ref remove_cpu_from_maps(int cpu)
  1135. {
  1136. cpu_clear(cpu, cpu_online_map);
  1137. cpu_clear(cpu, cpu_callout_map);
  1138. cpu_clear(cpu, cpu_callin_map);
  1139. /* was set by cpu_init() */
  1140. cpu_clear(cpu, cpu_initialized);
  1141. numa_remove_cpu(cpu);
  1142. }
  1143. void cpu_disable_common(void)
  1144. {
  1145. int cpu = smp_processor_id();
  1146. /*
  1147. * HACK:
  1148. * Allow any queued timer interrupts to get serviced
  1149. * This is only a temporary solution until we cleanup
  1150. * fixup_irqs as we do for IA64.
  1151. */
  1152. local_irq_enable();
  1153. mdelay(1);
  1154. local_irq_disable();
  1155. remove_siblinginfo(cpu);
  1156. /* It's now safe to remove this processor from the online map */
  1157. lock_vector_lock();
  1158. remove_cpu_from_maps(cpu);
  1159. unlock_vector_lock();
  1160. fixup_irqs();
  1161. }
  1162. int native_cpu_disable(void)
  1163. {
  1164. int cpu = smp_processor_id();
  1165. /*
  1166. * Perhaps use cpufreq to drop frequency, but that could go
  1167. * into generic code.
  1168. *
  1169. * We won't take down the boot processor on i386 due to some
  1170. * interrupts only being able to be serviced by the BSP.
  1171. * Especially so if we're not using an IOAPIC -zwane
  1172. */
  1173. if (cpu == 0)
  1174. return -EBUSY;
  1175. if (nmi_watchdog == NMI_LOCAL_APIC)
  1176. stop_apic_nmi_watchdog(NULL);
  1177. clear_local_APIC();
  1178. cpu_disable_common();
  1179. return 0;
  1180. }
  1181. void native_cpu_die(unsigned int cpu)
  1182. {
  1183. /* We don't do anything here: idle task is faking death itself. */
  1184. unsigned int i;
  1185. for (i = 0; i < 10; i++) {
  1186. /* They ack this in play_dead by setting CPU_DEAD */
  1187. if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
  1188. printk(KERN_INFO "CPU %d is now offline\n", cpu);
  1189. if (1 == num_online_cpus())
  1190. alternatives_smp_switch(0);
  1191. return;
  1192. }
  1193. msleep(100);
  1194. }
  1195. printk(KERN_ERR "CPU %u didn't die...\n", cpu);
  1196. }
  1197. void play_dead_common(void)
  1198. {
  1199. idle_task_exit();
  1200. reset_lazy_tlbstate();
  1201. irq_ctx_exit(raw_smp_processor_id());
  1202. c1e_remove_cpu(raw_smp_processor_id());
  1203. mb();
  1204. /* Ack it */
  1205. __get_cpu_var(cpu_state) = CPU_DEAD;
  1206. /*
  1207. * With physical CPU hotplug, we should halt the cpu
  1208. */
  1209. local_irq_disable();
  1210. }
  1211. void native_play_dead(void)
  1212. {
  1213. play_dead_common();
  1214. wbinvd_halt();
  1215. }
  1216. #else /* ... !CONFIG_HOTPLUG_CPU */
  1217. int native_cpu_disable(void)
  1218. {
  1219. return -ENOSYS;
  1220. }
  1221. void native_cpu_die(unsigned int cpu)
  1222. {
  1223. /* We said "no" in __cpu_disable */
  1224. BUG();
  1225. }
  1226. void native_play_dead(void)
  1227. {
  1228. BUG();
  1229. }
  1230. #endif